As a discharge valve operating device that performs a valve opening operation of a discharge valve of a flush water tank device that supplies flush water to a toilet, there has been known a discharge valve operating device in which an operation handle is rotationally operated in a predetermined direction manually, whereby a common rotary winding member is rotationally operated in a predetermined direction, the rotary winding member winds up a single operation wire connected to a discharge valve, and a valve opening operation is performed, as described in Patent Literature 1 (Japanese Patent Unexamined Publication No. 2014-190131).
Further, in a conventional discharge valve operating device described in Patent Literature 2 (Japanese Patent Unexamined Publication No. 2015-196949), there is also known the device that enables a valve opening operation by manually pulling up a single common operation wire linked to a discharge valve by a manual operation unit, and enables a valve opening operation by automatically pulling up a single common operation wire by an electric drive unit.
Further, in the conventional discharge valve operating device described in Patent Literature 2, a pulling-up amount of the operation wire is set to be large when a full-flushing mode in which a flush water amount is large is executed, and the pulling-up amount of the operation wire is set to be smaller than the pulling-up amount in the full-flushing mode when a partial-flushing mode in which the flush water amount is small is executed.
However, in recent years, in order to pursue ease of use of the discharge valve operating device, automation of the valve opening operation of a discharge valve has been realized by electrification of the operation itself of the discharge valve operating device or the like, without sticking to a direct manual operation by a user, and it has been a problem requested to be solved in recent years how to switch a flushing mode with an easy operation to perform a valve opening operation accurately.
Accordingly, the present invention is made to solve the problem requested to be solved in the aforementioned prior art, and has an object to provide a discharge valve operating device that can accurately perform a valve opening operation by switching a flushing mode with an easy operation, a flush water tank device, and a toilet system.